<?php
/**
 * Copyright (c) Enalean, 2014. All Rights Reserved.
 *
 * This file is a part of Tuleap.
 *
 * Tuleap is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Tuleap is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Tuleap. If not, see <http://www.gnu.org/licenses/>.
 */

abstract class Tracker_XML_Exporter_ChangesetValue_ChangesetValueXMLExporter {

    abstract protected function getFieldChangeType();

    abstract public function export(
        SimpleXMLElement $artifact_xml,
        SimpleXMLElement $changeset_xml,
        Tracker_Artifact $artifact,
        Tracker_Artifact_ChangesetValue $changeset_value
    );

    /**
     * @return SimpleXMLElement
     */
    protected function createFieldChangeNodeInChangesetNode(
        Tracker_Artifact_ChangesetValue $changeset_value,
        SimpleXMLElement $changeset_xml
    ) {
        $field = $changeset_value->getField();

        $field_change = $changeset_xml->addChild('field_change');
        $field_change->addAttribute('field_name' , $field->getName());
        $field_change->addAttribute('type' , $this->getFieldChangeType());

        return $field_change;
    }

    protected function isCurrentChangesetTheLastChangeset(
        Tracker_Artifact $artifact,
        Tracker_Artifact_ChangesetValue $current_changeset_value
    ) {
        $field          = $current_changeset_value->getField();
        $last_changeset = $artifact->getLastChangeset();

        if (! $last_changeset) {
            return false;
        }

        $last_changeset_value = $last_changeset->getValue($field);

        if (! $last_changeset_value) {
            return false;
        }

        return ($last_changeset_value->getId() === $current_changeset_value->getId());
    }
}
